Order equid mammals: characteristics, classification and conservation status. Artiodactyls: who belongs to them? What is a cloven-hoofed animal?

Artiodactyls are a family of mammals. There are 242 species of them.

Due to the fact that these animals have hooves, they are called the artiodactyl order. Such animals usually have two or four fingers.

The artiodactyl order is herbivorous. A detachment of artiodactyls lives in families. Due to natural changes, some artiodactyls carry out seasonal migrations.

The order of artiodactyls can be hunted by animals such as cats and dogs. People are also enemies of artiodactyls. They kill them for meat and skin.

The order Artiodactyls is divided into calloseds, ruminants and non-ruminants. Let's take a closer look at the class of ruminant artiodactyls.

This order of ruminant artiodactyls includes:

Giraffidae family

The giraffe family includes two species: giraffes and okapi. Let's look briefly at each type.

Giraffes.

The giraffe is the tallest animal that lives in the savannas of Africa.

Giraffes grow up to six meters tall and weigh a ton. Its legs are long, and its front legs are longer than its hind legs. The tail is long, reaching one meter. There are bony horns on the head. The eyes are large and the tongue is very long - 45 centimeters.

They lie down very rarely. Even giraffes sleep standing up. These animals move very quickly. Their speed can reach sixty kilometers per hour.

Giraffes live in herds of up to twenty individuals. Life expectancy is fifteen years.

Okapi.

Okapi resemble a horse, but are related to the giraffe. They have another name - forest giraffe. They live in the mountains and plains of the Republic of Congo.

This animal has a very interesting coloring: the legs are like a zebra's, that is, with black and white stripes. The muzzle is black with white spots, on top there are horns like a giraffe. Females do not have such horns.

The body is dark brown. The tail is long - forty centimeters. The animal reaches two meters in length. And the height is almost two meters. They weigh on average 250 kilograms. The tongue is long and blue, its length is thirty centimeters. The ears are large and sensitive.

Due to the decrease in the number of okapi, they are listed in the Red Book.

Deer family.

The deer family includes two genera of deer:

• Asian deer;
• Water deer.

Asian deer- These are the smallest ruminant ungulates. They live in the forests of Asia. Their body length reaches seventy centimeters. And the weight does not exceed eight kilograms. Deer have no antlers. The fur color of Asian deer is brown. They are only nocturnal.

Water deer- larger than Asiatic deer. Their body length reaches one hundred centimeters. Body weight reaches fifteen kilograms. And these deer don’t grow antlers either, but the males have long upper canines. They are nocturnal, like Asiatic deer. Coat color is brown.

Musk deer family

The musk deer family includes only one genus - musk deer.

Musk deer- This is an unusual animal that has fangs. They are located on the upper jaw.

These animals live in the mountains in northern Russia, as well as in China, Kyrgyzstan, Kazakhstan, Mongolia, Vietnam, Nepal, and Korea.

The length of these animals is small - one meter, and the height is eighty centimeters. The weight of musk deer does not exceed eighteen kilograms.

This amazing animal eats lichens, epiphytes, blueberry leaves, pine needles and ferns.

The life expectancy of these animals is very short - five years. And only in captivity they can live no more than twelve years.

Deer family

Deer family- belongs to the order of ruminant artiodactyls that live in America, Europe, and Africa.

The entire deer family has branched and long antlers, which they shed in winter. Females do not grow such horns. The horns of males are very heavy, approximately thirty kilograms. And their length can reach two meters.

The size of deer can vary. Some are as tall as a dog, while others are as tall as a bull.

Deer feed on leaves, shoots of bushes and trees.

The deer family consists of three subfamilies, nineteen genera and fifty-one species. The most interesting are the following:

• Red deer are the largest deer. Their weight can reach three hundred kilograms.
• The white type of deer is the rarest deer with a white coat.
• The American species is the white-tailed deer. They live in North America.
• Siberian breed. It includes the following breeds: Even, Chukchi, Evenki, Nenets.
• Pudu is the smallest species of deer. His height does not exceed forty centimeters, and his weight does not exceed ten kilograms

Bovid family

The bovid family includes:

• Buffaloes;
• Bison;
• Bulls;
• Rams;
• Goats;
• Antelopes;
• Gazelles.

Let's look briefly at each type.

Buffaloes.

The buffalo is a very dangerous animal, especially for humans. Statistics show that more than two hundred people die from this animal every year.

The weight of the buffalo reaches a ton, its height is two meters, and its length is more than three meters.

These animals feed exclusively on grass. Every day they eat twenty kilograms of fresh grass.

Buffaloes have huge horns that curl inward.

Bison.

The bison is a very powerful and strong animal. It is often confused with the bison. They reach three meters in length and two meters in height. Weight ranges from 700 to 1 thousand kilograms.

Bison live in western and northern Missouri. These animals live in herds. Their number consists of twenty thousand individuals. The bison eats only grass. He eats up to twenty-five kilograms of fresh grass a day.

The life expectancy of a bison does not exceed twenty-five years.

Bulls.

The bull is a cloven-hoofed ruminant mammal. There are the following types of bulls:

• Wild bull - lives in nature, is the predecessor of the domestic bull.
• Domestic bull - bred by humans for milk, meat and leather.
• The musk ox is the only representative of the musk oxen.
• Tibetan bull. This animal is called differently - Yak. It differs from other bulls in its hair, which hangs from the sides and covers the legs.

Rams.

A ram is a mammal. Its length can reach 180 centimeters, height 130 centimeters, and weight from 25 to 220 kilograms. A distinctive feature of these animals is their horns. They are very large, massive and twisted.

Rams are divided into the following types:

Goats.

A goat is a ruminant animal. They are domestic and wild. Most goats have a beard. The coat, depending on the breed, can be short or long. The horns are long and curved back.

The lifespan of goats does not exceed ten years.

Antelope.

Antelopes are a subfamily of bovids. Their body length ranges from twenty centimeters to two meters.

Gazelles.

The gazelle is a small animal that belongs to the antelope subfamily. The length of the gazelle does not exceed 170 centimeters, height - 110 centimeters, and weight - no more than 85 kilograms.

The gazelle's horns are long and lyre-shaped. Their length can reach eighty centimeters.

Basically, these animals live in Africa. Gazelle live in herds consisting of thousands of individuals.

Artiodactyls ( Artiodactyla) are the most diverse, large, terrestrial living today. It is the fifth largest, consisting of 10 families, 80 genera and approximately 210 species. Although most artiodactyls live in relatively open environments, they can be found in a wide variety of environments and on every continent except Antarctica, Australia and Oceania. As you would expect in such a diverse group, there are animals with a wide range of body shapes and weights. Body weight ranges from 1 kg (Asian deer) to 4000 kg (). The height of the animals varies from 23 cm (Asian deer) to 5 m ().

Classification

Artiodactyls are divided into 3 suborders:

• Non-ruminant or porcine ( Suina) includes 3 living families: peccaries, hippopotamuses and pigs, as well as two extinct ones - anthracotheriums and entelodonts. These animals are distinguished by a simple digestive system and weak specialization. They have rounded teeth and tusk-like fangs.
• (Ruminantia) include the families of deer, deer, giraffidae, pronghorn, musk deer and bovids, as well as a number of extinct families. Unlike non-ruminant animals, representatives of this order have a complex digestive system. They lack upper incisors, but ruminants have a dense callosum.
• Callosefoot ( Tylopoda) contain one living family of camelids. Modern callosopods have a 3-chambered stomach. They have two-fingered limbs, with blunt, curved claws. The feet of these animals have soft, calloused growths, thanks to which representatives of this order got their name.

Note: if we classify artiodactyls from the point of view of phylogeny, then they should be considered along with. These two orders form the superorder Cetaceans. (Cetartiodactyla).

Evolution

Like many mammals, artiodactyls first appeared during the early. In appearance, they were more similar to today's deer: small, short-legged animals that fed on leaves and soft parts of plants. By the late Eocene, the ancestors of three modern suborders had already appeared. However, at that time, artiodactyls were far from being modern, but were much more successful and numerous. Artiodactyls occupied minor ecological niches, and it appears that at this time they began to develop their complex digestive systems, which allowed them to survive by digesting low-quality food.

The appearance of grass during the Eocene and its subsequent spread during the Eocene marked major changes: grass was very difficult to eat, and artiodactyls with well-developed stomachs were better adapted to this roughage and soon replaced equids, the dominant terrestrial herbivores.

It was discovered that cetaceans evolved from artiodactyls, and the early whale from 47 million Eocene sediments had a double ankle joint. Some taxonomies place cetaceans and artiodactyls in the superorder Cetartiodactyla as sister orders, although DNA analysis has shown that cetaceans are from artiodactyls.

The most recent theory in the origins of hippopotamuses suggests that hippos and whales share a common semi-aquatic ancestor that diverged from other artiodactyls about 60 million years ago. The group of hypothetical ancestors probably split into two branches about 54 million years ago. One branch evolved into cetaceans, possibly starting with the proto-whale Pakicetus from 52 million years ago and other ancestors of early whales known as archaeocetes, which eventually underwent aquatic adaptation and became fully aquatic cetaceans.

Description

All artiodactyls have an even number of developed toes on each foot (although there is conflicting information about the number of toes on the hind feet of several species of the peccary family). The symmetry of the foot runs between the middle two toes and the weight of the animal is transferred most of all to them. The other toes are reduced in size, vestigial, or absent.

Another important characteristic is the shape of the astragalus. The astragalus is the ankle bone in the hind limb. It has deep arched grooves, and connects to the limb bones on both sides. These grooves give the leg greater flexibility and further increase the elasticity of the lower part of the hind limb.

Artiodactyls vary greatly in appearance: some have very long necks, while others have short ones; some have elongated muzzles, while others have short muzzles, etc. Female artiodactyls have two to four teats, but members of the pig family have six to twelve teats.

Almost all species have some kind of weapon, be it branched horns, forked horns or well-developed fangs or tusks. They are usually large in males and small or absent in females. The tail consists of longer, stronger guard hairs and shorter undercoat.

Digestive system

Artiodactyls have one or more digestive chambers located in front of the glandular stomach (abomasum). Most members of the suborder Ruminants ( Ruminantia) have a four-chamber stomach, consisting of such sections as: rumen, mesh, book and abomasum. This suborder includes ruminant mammals such as cattle, goats, sheep, giraffes, American bison, European bison, yaks, Asiatic buffalo, deer, etc.

Nevertheless, deer (family Tragulidae) within the suborder Ruminantia Ruminantia have a three-chamber stomach. Likewise, members of the suborder Callosopods Tylopoda(camels, alpacas, llamas) have a three-chambered stomach.

Note: all of these animals are still considered "ruminants", although camels are not included in the suborder Ruminantia. This is because the term ruminant simply means any artiodactyl that digests food in two stages, first softening it in the first stomach, known as the rumen, then regurgitating the semi-digested mass, now known as the cud, and chewing it again. Therefore, the term "ruminant" is not synonymous Ruminantia.

Pigs and peccaries have only one small chamber in front of the abomasum, while hippopotamuses have two. While hippos have a three-chambered stomach, they do not “chew the cud.” Hippos consume grass during the night and during this time they eat about 68 kg. They depend on microorganisms that process rough fiber in their stomach.

Most pig species have a simple two-chambered stomach that allows for an omnivorous diet; babirussa, however, is a herbivore. They have extra teeth to ensure proper chewing of plant material. Most fermentation occurs in the cecum with the help of cellulolytic microorganisms.

Habitat

Since artiodactyls are a fairly diverse order, they are distributed throughout the world. Consequently, these animals live in a wide range of habitats and can be found where sufficient food exists. Although these animals are common from to and to, the preferred ones are:

• open: they provide artiodactyls with an abundant amount of food, and also allow them to spot predators at a long distance.
• pastures or meadows near steep cliffs: provide food for animals and provide relatively safe shelter in rocks and steep terrain.
• and shrubs: contain an abundance of food and offer shelter from potential predators in dense vegetation.
• ecotone: is an area between open areas and forests. While open areas provide abundant food, adjacent forests provide good cover from potential predators.

Preference for particular habitats is often related to the body size and taxonomy of artiodactyls. For example, most species of goats and sheep ( Caprinae) are found in open habitats adjacent to rocky cliffs, where they have adapted to move around uneven terrain.

Reproduction

Most artiodactyls have a polygynous reproductive system, although some species are seasonally monogamous (for example, the blue duiker). Artiodactyls usually breed only once a year, although some of them can breed several times. The gestation period varies from 4 to 15.5 months. In addition to pigs, which can give birth to up to 12 young at a time, other artiodactyls give birth to up to two young, once a year. The weight of artiodactyls at birth can vary from 0.5 to 80 kg. Puberty occurs between 6 and 60 months of age. The cubs of all artiodactyls are able to walk independently within a few hours after birth, and some are already running after 2-3 hours. Females care for their offspring and feed them with their milk for 2-12 months after birth.

Lifespan

The lifespan of artiodactyls varies between 8-40 years. A large number of studies have shown that the survival rate of adult males is lower than that of females. These rates are thought to be the result of increased polygyny, which leads to increased competition between males. Research also shows that aging-related mortality begins before about age eight for some species of artiodactyls, regardless of sex.

Behavior

The social behavior of artiodactyls varies depending on the species. Although some artiodactyls are solitary, most are quite social. It is believed that even-toed ungulates that live in large groups eat more vegetation because they do not have to constantly scan the area and watch for approaching predators. However, if the group size increases sufficiently, competition within the same species may occur.

Species living in groups often have a hierarchy among both males and females. Some species also live in harem groups, with one male, several females and their shared offspring. In other species, females and young remain together while males are solitary or live in bachelor groups, seeking females only during mating season.

Many artiodactyls are territorial and mark their territory, for example, with specialized glands, feces or urine. There are species that migrate seasonally, while others remain in the same habitat throughout the year. Artiodactyls can be diurnal, crepuscular, or nocturnal. In some species, the period of wakefulness varies depending on the season or habitat.

Meaning for humans

Artiodactyls have great historical and current economic and cultural value. They served as large game for early hunters. The Cro-Magnons relied heavily on deer for food, hide, tools and weapons. About 12,500 years ago, deer remains made up 94% of the bones and teeth discovered in a cave above the Seu River in France.

Today, many artiodactyl species are still hunted for food and sport (deer, antelope, African buffalo, wild sheep, etc.). In addition, the most important domestic animals are artiodactyls, including cattle, goats, sheep, pigs and camels. Sheep and goats were probably the first animals to be domesticated since dogs, perhaps 8,000 to 9,000 years ago. Livestock farming is now the backbone of a multi-billion dollar industry worldwide. Artiodactyls, both wild and domesticated, are used by people for meat, fur, milk, fertilizers, medicines, bones, etc.

Artiodactyls and odd-toed ungulates are two orders of the class Mammals. Due to the similar sound and relative similarity of both groups of animals, identifying the differences between them poses a certain difficulty for schoolchildren.

Odd-toed ungulates- one of the orders of Mammals.

Comparison

Artiodactyls are an order of Mammals. It includes 3 suborders:

• ruminants - deer, giraffes, bulls, pronghorns, sheep, bison and antelopes;
• calloused - camels;
• non-ruminants - hippopotamuses, pigs and peccaries.

Artiodactyls are animals whose developed ends of the third and fourth classes are covered with a special case - the hoof. At the same time, their first finger is reduced, and the second and fifth are underdeveloped.

Artiodactyls are large and medium-sized animals. They have a characteristic elongated muzzle, and ruminants also have the obligatory decoration in the form of horns.

Artiodactyls are common on all continents except Antarctica. Initially, they were not only in Australia, but man “corrected” this oversight of Nature. Most of them live in open spaces (savannas, deserts, tundra, steppes). A minority of the squad chose the forest to live.

Deer. Order Artiodactyls

Odd-toed ungulates are a group of Mammals. Today, only 3 families of the once numerous taxon remain on Earth:

• the Equine family - horses, zebras and donkeys;
• Tapirov family;
• Rhino family.

Odd-toed ungulates are animals whose hoofs “cover” an odd number of toes.

Even-toed ungulates were once common on all continents except Antarctica and Australia. But in the wild, representatives of certain families can only be found in Africa, South and Central America, and Southeast Asia.

In addition to the number of phalanges forming the limbs, another characteristic difference between the two orders of these animals, which formed the basis of the taxonomy, is the structure of the digestive system. The fact is that in equids the main digestion of food occurs in the large intestine, and in artiodactyls - in the stomach. Therefore, in equids the stomach is single-chambered, while in artiodactyls it consists of four sections - the rumen, the mesh, the book, and the abomasum.

Conclusions website

1. In artiodactyls, a pair of toes form the hoof; in equids, the hoof “covers” an odd number of toes.
2. Artiodactyls in the wild are more common than equids.
3. Artiodactyls have a more complex digestive system and a multi-chambered stomach.

Ungulates with the number of fingers, both on the front and hind limbs, are two or four. The third and fourth fingers are more developed than others. The axis of symmetry of the limb runs between them, and these two fingers bear the main weight of the animal’s body. The second and fifth fingers are to one degree or another underdeveloped, sometimes completely absent. Homologous phalanges of functioning fingers have a mirror similarity (as if a reflection of one another). The third phalanx is laterally compressed and has an asymmetrical triangular shape. The third trochanter (trochanter tertius) is absent on the thigh. The femoral neck in artiodactyls clearly separates the articular head from the body of the bone. The intertrochanteric ridge runs from the greater to the lesser trochanter and borders the trochanteric fossa on the lateral and distal sides. The talus has two articular blocks: a proximal one for articulation with the bones of the lower leg and a distal one. The calcaneus of artiodactyls, in addition to the talus, always articulates with the fibula or its rudiment.

The sum of the number of thoracic and lumbar vertebrae is 19 - 20, sacral - typically 4.

The skull of artiodactyls is characterized by the absence of a basisphenoid at the bases of the pterygoid processes. The anterior margin of the choanae rarely extends forward further than the second posterior tooth. The articular fossa for the articulation of the lower jaw, in comparison with equids, is less elongated in the transverse direction, wider (in camelids it is even round); the postarticular process is low or completely absent; therefore, the lower jaw can make movements not only lateral, but sometimes also in the anteroposterior direction. Tympanicum has the shape of a more or less elongated and swollen bladder (bulla), forms not only the outer, but also most of the inner wall of the tympanic cavity. Characterized by the small size of the stony part (petrosum), which, like in equids, does not fuse with other bones. The sagittal crest is present only in the skull of Tylopoda and Tragulidae. The nasal bones are rarely very widened in the posterior half. If the orbit has a closed ring, then its posterior edge is formed only by the frontal process of the zygomatic and the zygomatic process of the frontal bone. The squamosal bone does not participate in the formation of the posterior edge of the orbit.

The molars of artiodactyls are of the selenodont or bunodont type; in some cases, they do not form a closed row. Permanent anterior roots (premolars), even the last of them, never take the form of posterior roots (molars) and are much simpler in structure. The last primary premolar, as well as the last molar of the mandible, always consists of three lobes. In some cases, four premolars are preserved in a series of permanent teeth. In these cases, the diastema may be absent. The incisors and canines in the upper jaw are often severely reduced or completely absent. The canines of the lower jaw are often shaped like the adjacent incisors.

The lips of artiodactyls are of various shapes. The front part of the head then takes on the character of a short trunk. The stomach of all modern forms is more or less complicated and consists of 2-4 chambers separated from each other to varying degrees. The mucous membrane with squamous stratified epithelium, devoid of digestive glands, lines a significant, usually most part of the stomach. The cecum and colon are less voluminous than in equids; isolated taenia and pocket-like protrusions on them are present only in non-ruminants. The colon forms a spiral in the form of a cone or disk. Gallbladder, with the exception of fam. Cervidae, available. Nasal drums and retropharyngeal air sacs are not developed in artiodactyls. The mammary glands are two- or four-lobed, inguinal; less often (in non-ruminants) multiple, located on the ventral side of the abdomen. The placenta is diffuse or cotyledonous. There can be several cubs in one litter (in domestic pigs up to 23).

Habitat and distribution of the artiodactyl order

The mainland and adjacent islands of Europe, Asia, Africa and America. Acclimatized in New Zealand. At home, they are distributed throughout the globe.

Evolution of artiodactyls

Like other branches of ungulates, artiodactyls originate from primitive Paleocene forms of one of the groups of primitive ungulates, Condylarthra. Some representatives of the latter (for example, the genus Hyopsodus Leidy) are almost no different in the structure of teeth and fingers from early artiodactyls. Almost simultaneously, in the lower and middle Eocene of Europe and America, the genera Diacodexis Soret, Homacodon .Marsh and Dichobune Cuvier appear, the shape of the talus with a double articular block leaves no doubt about their belonging to the order Artiodactyls. These were small animals, on low legs with four functioning toes, and on the forelimbs some apparently retained a small first toe. The low, elongated skull did not have a closed ring of the eye socket. The mastoid part of the petrous bone extended onto the facial surface of the skull. The teeth formed a continuous row without a diastema. The structure of the teeth indicates that these animals were not purely herbivorous, but ate a mixed diet. The molars of some forms of them also had a three-tubercle structure with blunted tops of the tubercles. This group (infraorder Palaeodonta) should be considered the source for all subsequent branches, including modern ones, Artiodactyla. Already by the Upper Eocene and Lower Oligocene, the number of groups of artiodactyls increased (giant two-hoofed entelodons, anoploteria, anthracotherium, early tragulids, camels and others), most of which became extinct, leaving no descendants in the modern fauna. Representatives of modern pigs, giraffes, deer and bovids appear only in the Upper Oligocene - Lower Miocene.

In the process of evolution, artiodactyls largely developed in parallel with equids. As in equids, the general direction of evolution is adaptation to rapid forward movements and feeding on plant foods. This is associated with varying degrees of pronounced reduction of the ulna and fibula, reduction and decrease in the number of lateral rays of the hand and foot, lengthening of the metapodia and phalanges of the fingers, the transition from plantigrade to digital and phalangeal walking, complication of the chewing surface of molars, and the development of hypsodontism. Of the modern forms, pigs and hippopotamuses are closest to the original state. Callouseds (Tylopoda), with complete reduction of the lateral rays, retained incomplete digitalization (resting on the second and third phalanges) and a claw instead of a hoof on the last phalanges.

The peculiar direction of the phylogenetic branch of artiodactyls is expressed, first of all, in the fact that in the earliest representatives of the order, the limbs, even if the first digit is preserved, have a “paraxonic” character, i.e., the axis of the limb passes between the third and fourth digits. In this regard, not one, but two named rays (III and IV) receive increased functional load and enhanced development. Hippos also have a third toe that is slightly longer than the fourth. For the rest they are already the same. The phalanges of the fingers of these rays acquire a mirror-like resemblance, and the metapodia tend to stick together and form a functionally single bone - the tarsus. The lateral rays (II and V) undergo reduction, and their fingers, as the central ones lengthen, cease to touch the soil. In extreme cases, they disappear completely or remain in the form of rudiments, devoid of a bone base. The process of strengthening the central and reducing the lateral rays occurred most quickly and found the greatest expression in forms adapted to fast running and to living on solid ground. The forelimbs in this regard were somewhat behind the hind limbs. The fusion of central metapodia and the disappearance of lateral digits in the phylogeny of all groups of artiodactyls occurred primarily in the foot, and not in the hand.

The second specific feature of artiodactyls from their earliest history is the formation of a double articular block on the talus (astragalus). In the process of evolution, the direction of the axis of the joint between the astragalus and the calcaneus (calcaneus) changed from oblique to perpendicular to the axis of the limb and parallel to the axis of the ankle joint. The resulting triple joint with parallel axes contributed to an increase in the range of flexor-extensor movements (flexion and extension), but almost completely excluded rotational ones (pronation and supination). In camels, for example, when the limb is flexed at the ankle joint while lying down, the shin and metatarsus acquire an almost parallel position to each other. The distal articular block of the astragalus probably contributed to jumping, one of the common modes of locomotion of some primitive modern (small antelopes), as well as early representatives of artiodactyls.

The original three-cusped type of molars in the process of evolution turns into four-, five- and even six-cusped. The tubercles are either rounded, turning the tooth into a bunodont one (pigs, hippos), or stretched into longitudinal curved semilunar ridges, which determine the characteristics of selenodont (lunate) type teeth in ruminants and camels. Teeth of the first type are adapted for omnivorous feeding or feeding on soft, succulent parts of plants. Selenodonty is associated with adaptation to chewing tough herbaceous foods. Some of the extinct groups (for example, Anthracotherium, Anoplotherium) had teeth of a mixed, bunoselenodont type. A wide articular surface for articulation with the lower jaw, allowing lateral movements of the latter, creates favorable conditions for more advanced function of the masticatory apparatus.

Adaptation to feeding on herbaceous foods in the evolution of artiodactyls was accompanied by a more complex stomach. In pigs and hippopotamuses, a not yet sharply isolated left-sided protrusion of the stomach wall is visible; The peccary's stomach already consists of three sections. It reaches its greatest complexity in the group of ruminants.

Literature:

1. I.I. Sokolov "Fauna of the USSR, Hoofed Animals" Publishing House of the Academy of Sciences, Moscow, 1959.

Artiodactyls
Some mammals have very hard claws. They are called hooves. They are big enough to walk on. Hence the name of these animals - ungulates. There are artiodactyls and odd-toed ungulates. Everyone is interested in one question: which animals are artiodactyls? As a rule, these are called placental mammals. Placental mammals have two or three fingers. They are further divided into ruminant and non-ruminant. Ruminant artiodactyls include deer, antelope, cattle, camel, llama, giraffe and okapi. and hippos.
Even-toed ungulates have four toes, short legs, molars and canines. Ruminants have longer legs with two toes, have chewing teeth, and a more developed digestive system than non-ruminants. Mammals that fall into this group chew the cud. Now we will look at the list of artiodactyl animals.

Hippos
Hippos are found only in Central, Western and Southern Africa. They live partly in water and partly on land. There are two types of hippopotamuses - ordinary and dwarf. The common hippopotamus, or hippopotamus, weighs up to 3,200 kg and is one of the largest land animals. Many artiodactyl animals spend most of the day in shallow bodies of water and emerge only at night. But pygmy hippos prefer to be near water, and they enter a reservoir only in case of danger. The hippopotamus' skin is hairless. Most common hippos are gray-brown in color, while pygmy hippos are black and brown. The gland secretion of the common hippopotamus is reddish in color and is often mistaken for blood. This secret makes the animal's skin shiny. It protects it from drying out in the sun. Pygmy hippopotamuses secrete the same secretion, only colorless, and it has the same purpose. Hippopotamuses' eyes are slightly bulging and located on the top of the head. Therefore, when swimming, these artiodactyl animals are above the water. Hippopotamuses' nostrils also point upward and can close tightly when diving.
Camels and llamas
Camels and llamas are ruminants. Even-toed ungulates of the llama genus are characterized by upper lips that are divided into two parts and are capable of moving separately from each other. There are two types of camels and four types of llamas. Camels are divided into two-humped (Bactrian) and one-humped (dromedary) camels, or Arabian camels. Contrary to popular belief, camels do not store water in their humps. Its humps contain a large amount of fat and serve as reserves of nutrients that are consumed during times of famine. Both artiodactyls are common in the deserts of Asia and North Africa.

Key facts
The black-footed antelope can jump over a fence 3 m high. In addition, the artiodactyl animal is able to cover a distance of 10 m in one jump.
The king antelope, which is only 25 cm tall, is the smallest antelope, while the kappa antelope, which can weigh up to 900 kg, is the largest species.
Giraffes can run at a speed of 56 km per hour, but it turns out that these artiodactyl animals cannot walk quickly - they have long legs.
Pygmy hippos are the smallest species of hippopotamus. Their height is only 75 cm, and their weight is about 160-270 kg.
Antelope and deer
Antelope is a ruminant with a pair of pointed, hollow horns. Most antelopes live in open grasslands, but some small even-toed ungulates prefer to live near forested areas so that in case of danger they can hide in dense foliage from predators. Those who live in open areas rely only on the speed of their feet and flee from their enemies. Unlike antelopes, deer have branched antlers, which they shed every year. Deer antlers are hard and bony. In deer, only males have antlers; in antelope, both males and females have antlers.
Giraffe
The giraffe is a cloven-hoofed animal. It is the tallest animal on Earth. An adult male can reach a height of 6 m. Giraffes live in savannas and forests. The giraffe's body is shorter than that of other artiodactyls. Its front legs are longer than its hind legs. Adult giraffes have very large hooves. The length of the animal’s neck reaches 1.5 m and consists of only a few vertebrae. These vertebrae are very long and separated from each other by movable joints. The long neck and unusually tall stature help the animals reach leaves where others cannot reach them. Giraffes have a very long tongue - they can stick it out 45 cm. Their tongue and lips are covered with hard growths, which allows them to eat leaves even from thorny trees. Both males and females have small horns covered with skin. Tufts of black fur grow at the tips of these horns.
Born for the desert
The Arabian camel is well adapted to life in the desert. It has wide pads and calluses on its soles - these calloused two-toed protrusions on its feet prevent them from becoming hot while standing on the hot desert sand. The Arabian camel's nostrils close to prevent sand from entering the nose. The eyelashes of artiodactyl animals are very long - they protect the eyes from heat and sand.
All the species that we have considered are artiodactyl animals of Africa. There are individuals that live outside the “Dark Continent”. Of course, there are species that are mistakenly considered representatives of this order.
According to many people, a horse is a cloven-hoofed animal. But in reality this is not the case; to be convinced, you just have to look at the structure of this species. There is only one developed toe on each leg and it is covered with a hoof.
Even-toed ungulates of the bovid family include several species. This order includes approximately 140 species. Among the most famous are bulls, gazelles, antelopes, buffaloes and bison. Here the main difference is only in one component - the horn. As a rule, there are two of them, the maximum length is 1.5 m. Some females do not have these outgrowths. No artiodactyl animal of the bovid family is characterized by branched horns. As a rule, such species live in open areas. The largest representative is the gaur, its height is 2.2 m. The minimum dimensions are observed in the royal antelope. She is no more tall than a domestic cat.

The artiodactyl animal of the deer family includes more than 50 species. Most of them live in Eurasia and America, and have recently been found in Australia (introduced). Sizes vary. The smallest representatives are as tall as a hare, and the largest are akin to horses. The horns are branched and are characteristic exclusively of males. Every artiodactyl of the bovid family loses its horns every year, but after 12 months they grow back. The beast begins its origins in the Oligocene.
Artiodactyl domestic animals.
This order includes those species that over many years have been able to find themselves among people. The latter keep such animals for food. Such animals reproduce without problems, passing on all their skills sexually. Humans have a huge influence on these animals. Most often, horses, goats, cows and sheep are found in the courtyards of villages and cities. Perhaps without these animals we could not exist at all.
- Far Eastern artiodactyl animal. In appearance, it resembles an ordinary pig that we are used to seeing in our farm yard. But this species is distinguished by well-developed fangs. As a rule, the length of such an animal is 205 cm and the height is 120 cm. The maximum weight reaches 320 kg. Unlike a pig, a boar's rear end is very low. That's why the animal sometimes seems poor and helpless. So, now you understand which animals are artiodactyls.